Endoscopes have long been widely used in medical procedures for directly visualizing the interior of a canal or body cavity. A recent improvement on the endoscope is the video endoscope, wherein fiber optics permit the endoscopic view to be displayed on a video monitor. Video endoscopy provides a number of advantages over traditional endoscopy, including permitting more than one person at a time to observe the endoscopic view, permitting the physician to assume a more comfortable viewing angle, and permitting a still photograph and/or videotape record to be made of the endoscopic procedure.
Similarly, modern fluoroscopic technology presents advances over conventional radiography. In conventional radiography, X-rays are projected through a patient onto a photographic film which, when processed, will provide a fixed image of the patient's internal structure In fluoroscopy, the X-ray sensitive photographic film is replaced by a fluorescent screen which, when subjected to X-radiation, produces a direct image of the object under investigation. Because the image on the fluorescent screen is usually so hint that it is difficult to visualize with the unaided eye, the screen image is usually photographed with a sensitive video camera. The video signal is then processed to increase the brightness of the image, and the image is displayed on a video monitor for viewing by the physician. Fluoroscopy affords two primary advantages over conventional radiography: first, the image produced is direct, so there is no need for photographic processing; and second, the image is viewed in "real time", rather than as a still photograph or series of still photographs, and can thus show movement.
Surgical modalities are well known wherein video endoscopy is used in conjunction with dye-injection studies under fluoroscopy at various times during the procedure. Examples of such procedures include endoscopic management of biliary tract obstruction and endoscopic sphincterotomy. In these procedures, the physician uses an endoscope to maneuver a catheter down the esophagus, through the stomach, and into position within either the bile duct or pancreatic duct. The endoscopic view is projected on a first video monitor. A quantity of radiographically opaque dye is then injected through the catheter retrograde into the selected duct. Subsequently, the duct is viewed fluoroscopically on a second video monitor, and the X-rays illuminate the dye to reveal obstructions in the biliary system. If the dye does not properly fill the duct, the catheter may have to be repositioned under endoscopic supervision to permit further infusion of dye. When further dye has been infused, the physician again views the duct fluoroscopically. After the procedure has been completed within the first duct, the physician uses the endoscope to reposition the catheter within the other of the bile or pancreatic duct, and the dye injection procedure is repeated. The physician then looks back to the fluoroscope monitor to visualize the second duct. Depending upon the success of the initial dye injection into the second duct, the physician may again have to redirect his attention to the endoscope monitor to reposition the catheter within the second duct, and then look back to the fluoroscope monitor to view the duct.
U.S. Pat. Nos. 4,993,404 and 5,127,394 disclose apparatus which simplifies this procedure somewhat by providing a control unit which displays both the endoscopic view and the fluoroscopic view on a single monitor. By depressing the foot pedal the physician can toggle back and forth between the endoscopic view and the fluoroscopic view. In addition, the control unit interfaces with the foot pedal which actuates the X-ray generator of the fluoroscope to ensure that the X-ray generator is enabled only when the fluoroscope view is being displayed on the monitor and is disabled when the endoscope view is selected for viewing on the monitor. This feature ensures that the X-ray generator will not be left on accidentally and thus prevents the possibility of the patient and medical personnel being exposed to unnecessary levels of X-rays.
Apparatus for performing medical procedures involving endoscopy and video fluoroscopy are further complicated by the need to record the procedure for future reference. Such recording can typically take any or all of three forms: videotape, still photographs, or magnetic recording and storage of still images for later display. A typical arrangement for endoscopy and video fluoroscopy incorporating recording and storage of images for later display is shown in FIG. 1. A video fluoroscope includes an X-ray generator actuated by a foot pedal. Video outputs from the video fluoroscope and an endoscope are fed into a photo archiving computer, that is, a component which stores and archives still video images on magnetic disk. An example of a photo archiving computer is the Image Manager, marketed by Olympus Corp. A keyboard is associated with the photo archiving computer for entering data, such as the name of the patient, etc. The photo archiving computer can output the endoscope video signal to a video tape recorder (not shown) and also to a still photograph unit (also not shown), which provides a "hard copy" of the endoscope video image at a particular instant. The endoscope video signal is then passed through the still photograph unit to a video monitor, which displays the endoscope video signal for viewing by the physician.
This arrangement is complicated by the fact that the fluoroscope video signal is in NTSC format, while the video endoscope, which can output a video signal in either NTSC or RGB video format, provides best resolution when operating in RGB mode. When the photo archiving computer is operating in RGB mode to receive the signal from the video endoscope, it cannot properly process the NTSC video signal from the video fluoroscope. Conversely when the photo archiving computer is operating in NTSC mode, it cannot properly process the RGB video signal from the endoscope. Consequently whenever the physician wishes to switch from the endoscope view to the fluoroscope view for archiving an image on magnetic disk, the physician must instruct the photo archiving computer to change its video mode of operation from RGB to NTSC, and when he wishes to switch back to the endoscope video signal he must instruct the photo archiving computer to change its video mode of operation from NTSC back to RGB. This selection of the video mode in which the photo archiving computer is to operate is conventionally accomplished by entering a predefined keyboard sequence. For example, in the aforementioned Olympus Image Manager, which is presently in widespread use, the physician toggles back and forth between RGB and NTSC video modes by entering a [control]-V-keystroke sequence on the photo archiving computer's keyboard. Thus whenever the physician wishes to switch from the endoscope view to the fluoroscope view for archiving an image on magnetic disk, the physician must enter a keystroke sequence to instruct the (photo archiving computer to select the appropriate video mode for operation while either he or an assistant activates the fluoroscope X-ray generator, captures the desired image(s), then deactivates the X-ray generator.
Thus there is a need for a video component for storing and archiving video images on magnetic disk which will select the appropriate video mode for operation without intervention by the physician.
There is a further need for a video component for storing and archiving video images on magnetic disk which will select the appropriate video mode for operation without intervention by the physician while minimizing exposure of the patient and attending medical personnel to X-rays from the fluoroscope.